The present disclosure relates to an information processing device, an information processing method, and a program. In further detail, the present disclosure relates to an information processing device, an information processing method, and a program which performs a process of executing a predetermined data conversion, generating conversion copy data, and recording onto a second medium at a time of copy processing of data which is recorded on a medium (information recording medium) such as a disc.
In recent years, DVDs (Digital Versatile Discs), BDs (Blu-ray Discs (registered trademark)), and the like are often used as information recording media for a variety of content such as movies, music, and the like. Creators, distributors, or the like of much of the content, such as music data and image data, which is recorded on the information recording media, have copyrights or distribution rights. Accordingly, there are certain limitations in the use of the content recorded on the disc even for the user which has purchased the disc. For example, performing of unlimited copying of the content recorded on the disc to media such as other discs is not permitted.
As a copy management configuration of content stored on a medium in this manner, a management configuration (MC: Managed Copy) is known where copying is permitted subject to copy permitted information being received from a management server. A detailed sequence of managed copying (MC) is as below.
A medium such as a disc which stores content is mounted into a user device such as a PC, a recording reproduction device, or the like and the user device connects to a management server via a network.
After that, the user device sends information prescribed in advance such as a disc identifier (ID) to the server.
After confirming the validity of the information received and the like, the server sends the copy permitted information to the user device.
The user device starts a copying process subject to the reception of the copy permitted information from the server.
The copying process of content stored on a disc with regard to other media is permitted using a sequence in this manner.
The copy management configuration is referred to as Managed Copying and the details are disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2008-98765.
On the other hand, there is an AACS (Advanced Access Content System) standard as a standard relating to content copyright protection technology. Much of the content stored on discs such as BDs in accordance with the AACS standard is recorded as encrypted content. As a representative encryption configuration of the AACS standard, there is a configuration where the content is partitioned into unit segments and encryption keys which differ for each unit are applied. By adopting an encryption configuration such as this, it is possible to control use of the unit segments of the content and various controls of the use of the content are strictly realized.
The unit which is a partition unit of the content is referred to as a CPS unit, and the encryption key which is applied to the encryption process and the decryption process of each of the CPS units is referred to as a CPS unit key, a unit key, or a title key.
In the user device such as that described above, in a case where copying of content stored on a medium, such as a BD (Blu-ray Disc (registered trademark)) where a movie or the like which is subject to copyright management is stored, is performed to another medium, for example, such as a hard disk, a flash memory, or another disc, copy permitted information is received from the management server and copying is executed in accordance with the Managed Copy described above.
However, if the content which is stored on a medium such as a BD (Blu-ray Disc (registered trademark)) is copied one after the other to, for example, a hard disk (HDD) which is a medium for copying, the amount of spare capacity on the hard disk which has a limited capacity is reduced and it is not possible to record large amounts of content.
As one method of solving a problem such as this, at a time of a copying process, there is a method of performing compression encoding of the copy data, generating video data or audio data with a higher compression rate, and recording in a copy destination. Alternatively, it is possible to reduce the amount of data by using a process for lowering the bit rate or selecting and copying only images, sounds, subtitles, or the like which is the minimum data necessary without performing copying of all data.
The processing of performing compression encoding and generating video data or audio data with a higher compression rate is performed by, for example, a transcoder which performs conversion of encoded data. For example, the transcoder performs a process of converting MPEG-2 encoded data stored in the original copying medium to AVCHD encoded data or MPEG4-AVC encoded data, changing of the compression rate, and removal of specific stream (second audio stream or the like). The AVCHD or MPEG4-AVC encoded data generated by the transcoder is recorded on a medium for copying (for example, a hard disk or the like).
Here, as a technology in the related art which describes the data conversion process, for example, there is Japanese Unexamined Patent Application Publication No. 2010-11511.
However, when data conversion is performed in this manner, there are cases where data format or control information of the data before conversion is lost or changed. As a result, there are cases where it is not possible to perform reproduction of the copy data, which is recorded on the medium for copying as conversion data, in the same manner as the reproduction of the original data.
As a specific example where a problem such as this occurs, for example, there is multi-angle content which includes captured images from a plurality of angles and where it is possible to switch and display the angle according to an input from a user. In a case where the multi-angle content is copied, there is a problem where there is a loss of or a change in information which is necessary for angle changing due to the data conversion executed at a time of a copying process and it is not possible to normally perform angle changing even when the copy data after conversion is reproduced.